Press belt and shoe press roll

ABSTRACT

A press belt ( 2 ) comprises both-end corresponding regions B positioned so as to correspond to both ends of a press roll ( 1 ) or a press shoe ( 3 ) in a width direction and having a small thickness and a center region A positioned between the both-end corresponding regions B and having a thickness larger than that of the both-end corresponding region B.

TECHNICAL FIELD

The present invention relates to a press belt and shoe press roll usedto press an object in various kinds of industries such as a paperindustry, a magnetic recording medium manufacturing industry, a fiberindustry and the like.

BACKGROUND ART

In various kinds of industries, belt press in which a continuous longobject to be pressed is put on a press belt and the object is pressedbetween one press member positioned inside the press belt and the otherpress member positioned outside the press belt is used. Here, the pressmember is a press roll or a press shoe. As an example of the belt press,there is a shoe press as dewatering press in the paper industry.

The shoe press will be briefly described taking the paper industry as anexample. It is a pressing (drying) method in which an object (wet paperweb) to be pressed is put on an outer peripheral surface of a press beltand pressed between a press roll positioned outside the press belt andserving as external pressing means and a press shoe positioned insidethe press belt and serving as internal pressing means, through the pressbelt. While linear pressure is applied to the object to be pressed inroll press using two rolls, area pressure can be applied to the objectto be pressed by using a press shoe having a predetermined width in atravel direction in the shoe press. Therefore, when the dewatering pressis performed by the shoe press, a nip width can be increased and adewatering effect can be enhanced.

In order to make the shoe press compact, as disclosed in JapaneseUnexamined Patent Publication No. 61-179359, for example, a shoe pressroll in which a press shoe serving as internal pressing means is coveredwith a cylindrical flexible press belt (press jacket) has been widelyused.

Other than the above dewatering process, in the paper industry, themagnetic recording medium manufacturing industry, the fiber industry andthe like, the shoe press is performed instead of the roll press ortogether with the roll press in order to improve quality of an object tobe pressed like a calendaring process in which a surface of the objectto be pressed is smoothed and glossed. General required characteristicsof the press belt includes strength, abrasion resistance, flexibility,impermeability to water, oil, gas and the like. As a material having theabove characteristics, polyurethane which is provided by reactingurethane prepolymer with a curing agent is used in the press belt ingeneral. However, since excessive bending or pressing is repeated on thepress belt, especially the shoe press belt, a crack which is likely tobe generated in the outer peripheral surface is a big problem in view ofresistance.

As a method of solving the above problem, Japanese Unexamined PatentPublication No. 10-298893 discloses a shoe press belt in which abrasionresistance and crack resistance is improved by differentiating hardnessof a resin which constitutes the belt so as to be high in a centerregion and low in both edge regions containing parts corresponding toshoe edges in a width direction. In this case, it is thought that thereis an effect that the abrasion resistance or pressed deformationresistance is maintained in the center region and the crack is noteasily generated in both edge regions.

The crack is likely to be generated intensively in both-endcorresponding regions which correspond to both ends of the pressingmeans in the width direction such as the press roll or the press shoe.Thus, it is thought that the crack resistance is not needed so much inthe center region positioned between the both-end corresponding regionsand serving as a pressing surface of the object to be pressed, but theabrasion resistance or the pressed deformation resistance should beconcerned in the center region.

Although a patent document 2 (Japanese Unexamined Patent Publication No.10-298893) is provided based on the above thought, in order to satisfyboth of the abrasion resistance and the crack resistance bydifferentiating hardness, it is necessary to largely differentiate thehardness of the center region from that of both edge regions. When thehardness of polyurethane is differentiated, contractive force at thetime of processing is varied. Therefore, according to the belt in whichthe hardness in the center region is largely differentiated from that inboth edge regions in the width direction, cylindricality is lowered andtraveling performance could be lowered.

In another prior art document, a crack is prevented from being generatedin both-end corresponding regions which correspond to both ends ofpressing means by improving a configuration or a structure of a pressbelt or differentiating a depth of a drainage groove (water-squeezegroove). For example, according to Japanese Unexamined PatentPublication No. 2002-180393, a thickness of a middle layer of a pressbelt positioned so as to correspond to both ends of pressing means in awidth direction is increased. In addition, according to JapaneseUnexamined Patent Publication No. 2002-327389, a bottom of a drainagegroove positioned so as to correspond to both ends of pressing means ina width direction is brought to come close to a reinforcing layer of amiddle layer. According to U.S. Pat. No. 5,943,951, flexibility isenhanced by varying a thickness of both ends of a press belt in a widthdirection gradually. According to U.S. Pat. No. 6,030,503, many recessedparts which are different from grooves are provided in both ends of apress belt in a width direction. According to Japanese Unexamined PatentPublication No. 11-12975, a depth of a drainage groove in both ends of apress belt in a width direction is reduced.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a press belt havinga more simple structure than before, in which a crack is effectivelyprevented from being generated in both-end corresponding regionspositioned so as to correspond to both ends of a press member in a widthdirection such as a press roll or a press shoe.

It is another object of the present invention to provide a shoe pressroll using the press belt as an external cylinder.

The press belt according to the present invention has an endlessconfiguration to be rotated, and it is used in a method in which anobject to be pressed is put on an outer peripheral surface of the pressbelt and the object is pressed by pressing means positioned insideand/or outside the press belt and having a predetermined width. Thepress belt comprises both-end corresponding regions positioned so as tocorrespond to both ends of the pressing means in the width direction andhaving a small thickness and a center region positioned between theboth-end corresponding regions and having a thickness larger than thatof the both-end corresponding region.

Stress is applied to the both-end corresponding regions of the pressbelt in traveling and width directions, so that twisting stress isapplied thereto. According to the constitution of the present invention,since the thickness of the both-end corresponding region is small,flexibility in this region is enhanced. Therefore, when the twistingstress is applied to the both-end corresponding region, since theboth-end corresponding region absorbs the twisting stress by flexibledeforming, the crack is effectively prevented from being generated.

In addition, the terms “travel direction” and “width direction” used inthis specification means a travel direction and a width direction of theobject to be pressed, respectively unless otherwise noted. In addition,the object to be pressed is a continuous long material such as a wetpaper web, a magnetic tape, a cloth and the like, which is notparticularly limited. In addition, the pressing means includes the pressroll or the press shoe.

According to one embodiment, an outermost region having the samethickness as that of the center region is provided outside the both-endcorresponding region. In general, a felt is placed between the pressbelt and the object to be pressed and the object passes through thepressing means together with the felt. When the outermost region of thepress belt has the same thickness as that of the center region, sinceboth ends of the felt in a width direction can be stably supported, freemovement of the felt can be controlled.

For example, the press belt comprises a reinforcing layer and an upperelastic layer formed thereon. In this case, a circular recessed part isprovided in the both-end corresponding region of the upper elasticlayer. Preferably, both opposed sidewall surfaces of the recessed partare tapered so that a distance between them is reduced toward a lowerside. Although there is a case where drainage grooves extending along abelt travel direction are spirally formed in the upper elastic layer ofthe press belt, when both sidewall surfaces of the recessed part areperpendicular wall surfaces, an intersecting part with the drainagegroove could be a steep edge. In order to prevent such steep edge frombeing generated, both sidewall surfaces are preferably tapered. Thereinforcing base material in the reinforcing layer is a woven cloth, forexample.

As describe above, many drainage grooves extending along the traveldirection of the belt may be formed in the outer peripheral surface ofthe upper elastic layer. In this case, preferably, a bottom surface ofthe recessed part is deeper than a bottom end of the drainage groove. Itis highly likely that a crack is generated in the bottom of the drainagegroove positioned in the both-end corresponding region of the pressbelt. According to this embodiment, since the thickness of the both-endcorresponding region is small and the drainage groove is not formed inthis region, the crack is effectively prevented from being generated.

When the press belt comprises the outermost region having the samethickness as that of the center region outside the both endcorresponding region, many drainage grooves may be formed in outerperipheral surfaces of the center region and the outermost region alongthe travel direction of the belt. When the drainage grooves are providedin the outermost region, since flexibility of the outermost region canbe enhanced, an effect of preventing the crack generation can beenhanced.

A press belt according to another embodiment comprises a reinforcinglayer and an upper elastic layer formed thereon. Both ends of the upperelastic layer are positioned at a boundary part between the centerregion and the both-end corresponding region. Preferably, both ends ofthe upper elastic layer are gently curved slant surfaces.

A press belt according to still another embodiment comprises areinforcing layer and an upper elastic layer formed thereon. The upperelastic layer has a tapered part in which a thickness is reduced outwardin a width direction, on the both-end corresponding region. A recessedgroove is formed in the middle of the tapered part so as to reduce itsthickness. When many drainage grooves extending along a travel directionof the belt are formed in the outer peripheral surface of the upperelastic layer, it is preferable that the recessed groove is deeper thanthe drainage groove.

In another aspect of the present invention, a press belt comprises areinforcing layer and an upper elastic layer formed on the reinforcinglayer, and the upper elastic layer comprises both-end correspondingregions positioned so as to correspond to both ends of the pressingmeans in a width direction and a center region positioned between theboth-end corresponding regions. This embodiment is characterized in thatmany drainage grooves extending along the travel direction of the beltare formed in the center region of the upper elastic layer but adrainage groove is not formed in the both-end corresponding region. Thecrack is easily generated in the bottom of the drainage groovepositioned in the both-end corresponding region. Thus, according to thisembodiment, the drainage groove is not formed in the both-endcorresponding region to prevent the crack from being generated. In thisembodiment, the thickness of the both-end corresponding region may bethe same as that of the center region.

In the above embodiment, an outermost region having a drainage groovemay be provided outside the both-end corresponding region. Since theflexibility of the outermost region is enhanced because of the drainagegrooves in the outermost region, the crack is more effectively preventedfrom being generated.

A shoe press roll according to the present invention comprises anexternal cylinder comprising an endless press belt, and press shoepositioned inside the cylinder as pressing means.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a sectional view showing a shoe press system in a traveldirection used in a press process of a paper machine;

FIG. 2 is a sectional view showing an essential part of a pressing anddewatering part P in a width direction in FIG. 1;

FIG. 3 are views showing a press belt according to one embodiment of thepresent invention, in which (a) shows its sectional view and (b) showsit plan view;

FIG. 4 is an enlarged sectional view showing one embodiment of thepresent invention;

FIG. 5 is an enlarged sectional view showing another embodiment of thepresent invention;

FIG. 6 is an enlarged sectional view showing still another embodiment ofthe present invention;

FIG. 7 is an enlarged sectional view showing still another embodiment ofthe present invention;

FIG. 8 is an enlarged sectional view showing still another embodiment ofthe present invention;

FIG. 9 is an enlarged sectional view showing still another embodiment ofthe present invention; and

FIG. 10 is a sectional view showing a shoe press roll in a widthdirection according to one embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with referenceto the drawings hereinafter.

FIG. 1 is a view showing a section of a shoe press system in a traveldirection used in a pressing process of a paper machine. The shoe presssystem comprises a press roll as pressing means 1, a press belt 2opposed to the press roll 1, and a press shoe positioned inside thepress belt 2 and serving as pressing means 3. In addition, according tothe system shown in FIG. 1, although a shoe press roll 30 is soconstituted that the press shoe 3 is covered with the press belt 2 andthe press belt 2 is assembled so as to be in the shape of a roll as anexternal cylinder, the press belt 2 is not necessarily assembled so asto be in the shape of the roll and it may be used as an endless belt asit is.

A size of this kind of the press belt 2 is 2 to 15 m in width and 1 to30 m in peripheral length and 2 to 10 mm in thickness in general.

The press roll 1 is positioned outside the press belt 2 and functions asone pressing means. The press shoe 3 is positioned inside the press belt2 and functions as the other pressing means. A wet paper web 5 to bepressed on which a felt 4 is provided passes between the press belt 2and the press roll 1. An outer periphery of the press belt 2 and thefelt 4 are directly in contact with each other.

Lubricating oil is supplied between the press belt 2 and the press shoe3 and the press belt 2 can slide on the press shoe 3. The press roll 1is driven to be rotated and the press belt 2 is rotated by frictionalforce with the traveling felt 4, sliding on the press shoe 3.

The press shoe 3 is pressed from the inside of the press belt 2 towardthe press roll 1 and the wet paper web 5 is pressed by this pressingforce and dewatered. A surface of the press shoe 3 is recessed so as tocorrespond to a surface of the press roll 1. Thus, a pressing anddewatering part P having a large width in the travel direction is formedbetween the press roll 1 and the press belt 2.

FIG. 2 is a sectional view showing an essential part of the pressing anddewatering part P in a width direction in FIG. 1. As shown in FIG. 2,the press roll 1 and the press shoe 3 have predetermined lengths in thewidth direction. The press belt 2 comprises a center region A, both-endcorresponding regions B, and outermost regions C. The both-endcorresponding regions B correspond to regions comprising both ends 7 ofa pressing surface 6 of the press roll 1 and both ends 9 of a pressingsurface 8 of the press shoe 3. The outermost region C is positionedoutside the both-end corresponding region B.

FIG. 3 are views showing an example of the press belt, in which FIG.3(a) shows its sectional view and FIG. 3(b) shows its plan view. Thepress belt 2 comprises an endless reinforcing layer 10 in which anelastic material is impregnated in a reinforcing base material, an upperelastic layer positioned on an outer periphery of the reinforcing layer10 and integrated with the elastic material impregnated in thereinforcing base material of the reinforcing layer 10, and an lowerelastic layer 12 positioned on an inner periphery of the reinforcinglayer 10 and integrated with the elastic material impregnated in thereinforcing base material of the reinforcing layer 10.

As the reinforcing base material constituting the reinforcing layer 10,a woven cloth comprising an organic fiber such as polyamide andpolyester is used. The entire belt 2 is integrally formed of an elasticmaterial such as thermosetting polyurethane and the reinforcing basematerial is buried in the belt 2.

As shown in FIG. 3, many drainage grooves 13 extending along the traveldirection of the belt are provided in the outer peripheral surface ofthe upper elastic layer 11. The drainage groove 13 extends spirally inthe press belt 2 throughout in the width direction.

FIG. 4 is an enlarged sectional view showing the press belt 2. In thepress belt 2, a thickness of the both-end corresponding region Bpositioned so as to correspond to both ends of the pressing means in thewidth direction is constituted so as to be smaller than that of thecenter region A and the outermost region C. More specifically, accordingto the upper elastic layer 11, the both-end corresponding region B is arecessed part 14 which circularly extends in the belt travel direction,so that the thickness of the both-end corresponding region B is smallerthan those of the other parts.

According to the embodiment shown in FIG. 4, when it is assumed that adepth of the drainage groove 13 is dl and a depth of the recessed part14 is d2, the depth of the drainage groove and the depth of the recessedpart 14 are selected so as to satisfy that d2≧d1. In this dimensionalrelation, the drainage groove 13 is formed in the center region A andthe outermost region C but the drainage groove is not formed in theboth-end corresponding region B.

Here, concrete dimensions will be exemplified. As describe above, thepress belt 2 is 2 to 15 m in its width, 1 to 30 m in peripheral lengthand 2 to 10 mm in thickness. According to such press belt 2, a widthdimension of the both-end corresponding region B is about 2 to 15 cm, athickness of the upper elastic layer 11 is about 1.2 to 3 mm, the depthd1 of the drainage groove 13 is about 0.5 to 1.5 mm, and the depth d2 ofthe recessed part 14 is about 1.2 to 3 mm. In addition, a width of thedrainage groove 13 is about 0.6 to 1.2 mm and a width of a land partpositioned between the adjacent drainage grooves 13 is about 0.9 to 3.6mm.

According to the embodiment shown in FIG. 4, the following advantagesare provided. First, since the thickness of the both-end correspondingregion B is reduced, flexibility of this region can be improved.Therefore, even when twisting stress is applied to this region, sincethe twisting stress can be absorbed by its flexible deformation to someextent, a crack can be prevented from being generated.

Secondly, since the recessed part 14 is formed in the upper elasticlayer positioned in the both-end corresponding region B, there is nodrainage groove in which the crack is likely to be generated, so that aneffect to prevent the crack generation is highly provided. Preferably,both sidewall surfaces 14 a of the recessed part 14 are tapered so thata distance between them is decreased toward the bottom. If both sidewallsurfaces 14 a of the recessed part 14 are perpendicular wall surfaces,an intersecting part between the perpendicular surface and the drainagegroove 13 could be a steep edge. In order to prevent such steep edgefrom being generated, both sidewall surfaces 14 a are preferablytapered. In addition, in order to avoid stress concentration in a bottomcorner part of the recessed part 14, the corner part may be curved.

Thirdly, since the outermost region C of the press belt 2 has the samethickness as that of the center region A, both ends of the felt in thewidth direction can be stably supported by the outermost regions C, sothat free movement of the felt can be controlled.

Fourthly, since the many drainage grooves are formed in the outerperipheral surfaces of the outermost region C along the travel directionof the belt, the flexibility of the outermost region C is enhanced, sothat the effect to prevent the generation of the crack is improved.

FIGS. 5, 6, 7, 8 and 9 show other embodiments of the press belt.

A press belt 20 shown in FIG. 5 comprises a reinforcing layer 21, anupper elastic layer 22 and a lower elastic layer 23. According to thisembodiment, drainage grooves 24 spirally extend in the upper elasticlayer 22 throughout in a width direction. A part corresponding toboth-end corresponding region B in the upper elastic layer 22 is arecessed part 25. A depth of the recessed part 25 is smaller than thatof the drainage groove 24. Thus, the drainage groove 24 is provided inthe bottom of the recessed part 25. According to this embodiment also,since the both-end corresponding region B having a small thicknessprovides preferable flexibility, the crack can be prevented from beinggenerated.

A press belt 40 shown in FIG. 6 comprises a reinforcing layer 41, anupper elastic layer 42 and a lower elastic layer 43. According to thisembodiment, there is no drainage groove provided. Since a partcorresponding to a both-end corresponding region B in the upper elasticlayer 42 is a recessed part 44, the both-end corresponding region Bprovides preferable flexibility.

A press belt 60 shown in FIG. 7 comprises a reinforcing layer 61, anupper elastic layer 62 and a lower elastic layer 63. Drainage grooves 64spirally extend in the upper elastic layer 62 throughout in a widthdirection. According to this embodiment, almost no upper elastic layeris formed on a both-end corresponding region B and an outermost regionC, so that the both-end corresponding region B and the outermost regionC are provided substantially on the same surface as the reinforcinglayer 61. Here, the term “substantially on the same surface” includes aconcept such that even if the upper elastic layer is remained, it is askin layer which is 0.5 mm or less in thickness. In addition, both ends65 of the upper elastic layer 62 positioned at a boundary part between acenter region A and the both-end corresponding region B are gentlycurved slant surfaces. Especially, upper and lower corner parts of theupper elastic layer are chamfered so as to be gently curved to avoidstress concentration.

A press belt 70 shown in FIG. 8 comprises a reinforcing layer 71, anupper elastic layer 72 and a lower elastic layer 73. Drainage grooves 74spirally extend in the upper elastic layer 72 throughout in the widthdirection. According to this embodiment, the upper elastic layer ishardly formed on an outermost region C and the outermost region C isprovided on the substantially same surface as the reinforcing layer 71.In addition, the upper elastic layer 72 positioned on a both-endcorresponding region B has a tapered part 75 in which its thickness isgradually reduced toward the outermost region C. As shown in FIG. 8, arecessed groove 76 which is deeper than the drainage groove 74 is formedin the middle of the tapered part 75. The tapered part 75 which reducesin thickness functions to absorb stress. In addition, since there is nodrainage groove in which the crack is likely to be generated provided inthe recessed groove 76, the crack can be prevented from being generatedin this part. In addition, a width of the recessed groove 76 is about 1to 10 cm.

A press belt 50 shown in FIG. 9 comprises a reinforcing layer 51, anupper elastic layer 52 and a lower elastic layer 53. According to thisembodiment, a recessed part is not formed. The upper elastic layer 52comprises both-end corresponding regions B positioned so as tocorrespond to both ends of the pressing means in a width direction, acenter region A positioned between the both-end corresponding regions B,and outermost regions C positioned outside the both-end correspondingregions B. Although many drainage grooves 54 extending along a belttravel direction are formed in the center region A and the outermostregion C of the upper elastic layer 52, the drainage groove is notformed in the both-end corresponding region B. According to thisembodiment, since the drainage groove in which the crack is likely to begenerated is not formed in the both-end corresponding region B, thecrack is prevented from being generated in this region.

Next, an embodiment of the shoe press roll 30 according to the presentinvention will be described with reference to FIG. 10. FIG. 10 is asectional view showing the shoe press roll in a width direction. Theshoe press roll 30 is constituted such that the press shoe 3 is coveredwith the press belt 2 serving as the pressing means and the press belt 2is assembled so as to be in the shape of a roll as an external cylinder.

The press shoe 3 is supported by a hydraulic cylinder 32 on a supportingaxis 31 and it can press the press belt 2 upward. An end disk 33 isrotatably supported on each end of the supporting axis 31 through abearing 34. An edge of the press belt 2 is bent on an outer periphery 36of the end disk 33 inside in a radius direction. The bent part of theedge of the press belt 2 is sandwiched between an outer periphery of theend disk 33 and a ring-shaped fix plate 35 and fixed by a screw bolt andthe like. Lubricant oil is supplied between the press belt 2 and pressshoe 3. Thus, the press belt 2 fixed to the end disk 33 can be rotated,sliding on the press shoe 3.

As the press belt 2, the press belt 2 described in the above embodimentscan be used.

Although embodiments of the present invention have been described withreference to the drawings, the present invention is not limited to theillustrated embodiments. Various kinds of modifications and variationscan be added in the same or the equivalent scope of the presentinvention.

INDUSTRIAL APPLICABILITY

The press belt according to the present invention can be used over along period of time because a crack is not likely to be generated in aboth-end corresponding region in which the crack is likely to begenerated before. Therefore, the present invention can be advantageouslyapplied to a press belt and shoe press roll used to press a material tobe pressed in various kinds of industries such as a paper industry, amagnetic recording medium manufacturing industry, a fiber industry andthe like.

1.-15. (canceled)
 16. A press belt in a press system comprising arotating endless press belt and pressing means positioned inside and/oroutside said press belt, comprising: both-end corresponding regionspositioned so as to correspond to both ends of said pressing means in awidth direction and having a small thickness; and a center regionpositioned between said both-end corresponding regions and having athickness larger than that of said both-end corresponding region. 17.The press belt according to claim 16, comprising an outermost regionpositioned outside said both-end corresponding region and having thesame thickness as that of said center region.
 18. The press beltaccording to claim 16, comprising a reinforcing layer and an upperelastic layer formed thereon, wherein said both-end corresponding regionin said upper elastic layer is a circular recessed part.
 19. The pressbelt according to claim 18, wherein both opposed sidewall surfaces ofsaid recessed part are tapered so that a distance between them isreduced toward a lower side.
 20. The press belt according to claim 18,wherein said reinforcing layer comprises a woven cloth.
 21. The pressbelt according to claim 18, wherein many drainage grooves extendingalong a travel direction of the belt are formed in the outer peripheralsurface of said upper elastic layer.
 22. The press belt according toclaim 21, wherein a bottom surface of said recessed part is at the samelevel as or deeper than a bottom end of said drainage groove.
 23. Thepress belt according to claim 17, wherein many drainage grooves areformed in outer peripheral surfaces of said center region and saidoutermost region along a travel direction of the belt.
 24. The pressbelt according to claim 16, comprising a reinforcing layer and an upperelastic layer formed thereon, wherein both ends of said upper elasticlayer are positioned at a boundary part between said center region andsaid both-end corresponding region.
 25. The press belt according toclaim 24, wherein both ends of said upper elastic layer is a gentlycurved slant surface.
 26. The press belt according to claim 16,comprising a reinforcing layer and an upper elastic layer formedthereon, wherein said upper elastic layer has a tapered part in which athickness is reduced outward in a width direction, on said both-endcorresponding region, and a recessed groove is formed in the middle ofsaid tapered part.
 27. The press belt according to claim 26, whereinmany drainage grooves extending along a travel direction of the belt areformed in an outer peripheral surface of said upper elastic layer, andsaid recessed groove is deeper than said drainage groove.
 28. A pressbelt in a press system comprising a rotating endless press belt andpressing means positioned inside and/or outside said press belt,comprising: a reinforcing layer and an upper elastic layer formed onsaid reinforcing layer, wherein said upper elastic layer comprisesboth-end corresponding regions positioned so as to correspond to bothends of said pressing means in a width direction and a center regionpositioned between said both-end corresponding regions, and manydrainage grooves extending along a travel direction of the belt areformed in the center region of said upper elastic layer and a drainagegroove is not formed in said both-end corresponding region.
 29. Thepress belt according to claim 28, comprising an outermost region havinga drainage groove outside said both-end corresponding region.
 30. A shoepress roll comprising an external cylinder comprising an endless pressbelt, and press shoe positioned inside said cylinder as pressing means,wherein said cylinder is the press belt according to claim 16.